In 1975, a year before the show as you know it premiered on television, a half-hour variety show titled The Muppet Show: Sex and Violence piloted on ABC. It was meant to “parody the proliferation of sex and violence on television." Dangerous Minds revisited the old pilot on YouTube, and note, "watching this pilot it’s clear that Henson and co. were aiming for a more adult-orientated, risqué edge to the material, akin to the sketches they provided in the very early years of Saturday Night Live (and which were deemed, in the end, not to work.)"
According to the Muppet Wiki page, it aired on March 19th, 1975, and was shot on December 10-16, 1974. "It was one of the two pilots produced for The Muppet Show. The other pilot, The Muppets Valentine Show, aired in 1974."
In other weird historical Muppet facts: Kermit used to be a... lizard!
